Signal connecting bolt



1958 L. w. ROMINE SIGNAL CONNECTING BOLT Filed April 18, 1957 INVENTOIQQ. 55 W. Kan/NE.

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Unite States Patent SIGNAL CONNECTING BOLT Lee W. Romine, Indianapolis, Ind.

Application April 18, 1957, Serial No. 653,685

4 Claims. (Cl. 200138) This invention relates generally to a combined signal and connector bolt, and particularly to a form of such apparatus which embodies a switch adapted to provide a signal upon over heating of an engine block.

This application is a continuation-in-part of my copending application Serial No. 431,761, filed May 24, 1954, and titled Combined Signal and Connector Bolt, now Patent No. 2,795,771. As stated in the aforementioned copending application, while every automobile has a temperature indicator, it is nonetheless true that because of the infrequency of its becoming significant or important, the average driver does not observe the indicator when high temperatures are shown thereon. Further, such conventional indicators reflect only the temperature of the water and but indirectly or remotely the heat of the block itself.

It is an object of the present invention to provide a combined signal and connector bolt which may be used in place of a conventional cylinder head bolt.

It is a further object of the present invention to provide such a combined signal and connector bolt which includes a switching apparatus actuated by heat conducted from the engine block to provide a warning signal.

The above-mentioned objects are accomplished by means of an apparatus which is rugged, simple in manufacture and assembly, and which has an extended trouble-free operational life. These and other objects of the present invention will become apparent as the description proceeds with reference to the accompanying drawing in which:

Fig. 1 represents a cross-sectional view of a preferred form of the invention shown mounted within an engine block.

Fig. 2 represents a top view of the apparatus shown in Fig. 1.

Fig. 3 represents an enlarged view of a portion of the apparatus shown in Fig. 1.

Shown generally at in Fig. 1, is an engine block underlying a head gasket 11 receiving thereon a cylinder head 12. Threaded into the opening normally provided for a conventional cylinder head bolt is a threaded shank portion 13 of a bolt embodying the present invention which carries at its upper end a cup-shaped housing mem ber 14. As may best be seen in Fig. 2, the base of the cup-shaped member 14 is carried on a hexagonal head 15 formed at the top of the shank portion of the bolt to facilitate its threaded insertion into the engine block.

The member 14 is joined to the upper end of the portion 13 by any suitable form of connection which provides good thermal conductivity between them. The member 14 is formed of a metal having high thermal conductivity and has an inwardly turned upper margin adapted to receive an appropriately shaped electrical insulating block 16. The depth of insertion of the block 16 into the member 14 is determined by copper spacers 17 and 18 having an annular form and being initially 2,863,024 Patented Dec. 2, 1958 pressed within the cup-shaped member 14 to thereby provide a good heat conducting joint between the side wall of the member 14 and the spacers. Extending centrally through the block 16 is an electrically conducting sleeve 17a having flanged margins holding the sleeve Within the block 16.

The inner end of the sleeve 17a is internally threaded to receive a contact carrying screw 18a having a contact face 19 at its lower extremity which extends from the sleeve 17a and into the cavity formed by the spacers 17 and 18. The upper end of the sleeve 17a is threaded to receive a terminal screw 21 adapted to accommodate a wire lead 22 which may be connected to the born or Klaxon of the automobile accommodating the signaling device.

Mounted between the spacers 17 and 18 is a bimetal thermally responsive member 23 having, as may best be seen in Fig. 3, an annular marginal portion and an extending portion 24 which carries a switch contact 25. It will be apparent that contact 25 is adapted to cooperate with the contact surface 19 provided by thescrew 18a and that the mounting of the member 23 between the copper spacers provides for good thermal conduction thereto from the shank portion 13, through the member 14 and through the spacers. It will be further understood that the spacers electrically connect the contact 25 through the member 14, the shank portion 13 and the-engine block to one side of the automobile electrical system, and the contact surface 19 is connected to the other side of the electrical system by means of the lead wire 22.

In operation, should the temperature of the block 10 rise abnormally, because of the heat conducting path from the engine block to the thermally responsive member 23, that member will respond relatively rapidly, moving the contact 25 into engagement with contact 19, thereby closing the electrical circuit to the apparatus connected to the lead wire 22 which, as previously mentioned, may be an automobile horn or similar signaling device. Calibration of the response of the apparatus just described may be accomplished by adjustably positioning the screw 18a within the sleeve 17a.

The foregoing has described an apparatus which is easily assembled, calibrated and installed. While the invention has been illustrated and described in detail the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the scope of the appended claims are also to be protected.

The invention claimed is:

1. A combined signal and connector bolt of the type which is inserted in standard threaded openings in a cylinder head and block to thereby join the same comprising a threaded shank portion for insertion into the cylinder head and block, a head portion including a metallic cupshaped member secured in good thermal conductive relation at its base to the shank portion, a switch contact block formed of electrical insulating material closing the open end of said cup-shaped member, an electrically conductive sleeve extending axially through the block and carrying a terminal screw threaded into its outer end, a switch contact forming screw threaded into its inner end, said contact screw extending into the cup-shaped member, a bimetallic thermally responsive member mounted within the cup-shaped member in thermal conductive relation therewith, and a movable switch contact carried by said thermally responsive member and cooperating with the inner end of said switch contact forming screw to provide a warning signal when the temperature at said shank portion reaches a predetermined value, adjustment of said contact forming screw Within the:

3 sleeve providing a means for calibrating the response of said thermally responsive member.

2. A combined signal and connector bolt of the type which is inserted in standard threaded openings in a cylinder head and block to thereby join the same comprising a threaded shank portion for insertion into the cylinder head and block, a head portion including a metallic cupshaped member secured at its base to the shank portion, a switch contact block formed of electrical insulating material closing the open end of said cup-shaped member, a stationary switch contact carried by the block Within the cup-shaped member, annular copper spacer members having thermally conductive contact with the side walls of the cup-shaped member and fixing the position the block within the cup-shaped member, a bimctanic thermally responsive element mounted between the spacer members having a contact carrying portion extending into cooperating relation with said stationary contact, movement of the extending portion of said thermally responsive element in response to heat conducted thereto through the cup-shaped member and said spacers serving to provide a warning signal when the temperature at said shank portion reaches a predetermined value;

3. An assembly as claimed in claim 2 having means for adjustably displacing the stationary contact relative to the block to calibrate the thermal response of the bimetal element.

4. In a motor vehicle including audible warning means and an engine block having threaded apertures normally occupied by conventional cylinder head bolts, the combination with one of said apertures of a combined connector and signal bolt threaded in one of said apertures in place of said conventional head bolt comprising a threaded shank adapted to fit in said apertures, a cupshaped head attached at its base to said shank in thermally conductive relation therewith, a pair of stacked annular heat conducting spacers pressed within the cupshaped head, a bimetallic thermally responsive member held between said spacers and having a contact carrying extension, an insulating block closing the open face of the cup-shaped head and carrying within the head a switch contact adapted to cooperate with said contact carrying extension to actuate said audible warning means upon a predetermined temperature being reached in the engine block.

References Cited in the file of this patent UNITED STATES PATENTS 1,653,685 Whittington Dec. 27, 1927 2,442,945 Andersen June 8, 1948 2,562,286 Wall July 31, 1951 

